FIG. 8.

Proposed topology of the BfpE protein. The amino acids composing BfpE are represented by circles. These are displayed in a manner that specifies their arrangement in the E. coli cytoplasmic membrane. HS1 through HS4 denote TM segments. Positively charged amino acids (arginines and lysines) that may be topology determinants are shaded. C-terminal fusion protein junctions are indicated by a line and the number of the terminal BfpE residue in the fusion. The insertion sites for the dual reporter in sandwich fusions are indicated by a restriction enzyme name.